Current Status in Diagnosis and Treatment of Hereditary Thrombotic Thrombocytopenic Purpura

Thrombotic Thrombocytopenic Purpura (TTP) is an acute and potentially fatal hematologic disorder. It is characterized by systemic platelet clumping in the microvasculature and small arterioles, resulting in thrombocytopenia and microangiopathic hemolytic anemia [1]. Some patients may present signs and symptoms that are consistent with end organ dysfunction [2]. The pathology of this disorder derives from the deficiency of plasma metalloenzyme ADAMTS13 (A Disintegrin and Metalloprotease with Thrombo Spondin type-1 repeats, 13) [3,4]. Under physiological conditions, ADAMTS13 cleaves ultra-large VWF (UL-VWF) that is released from endothelial cells upon activation or vascular injury [5-7]. This proteolytic cleavage of UL-VWF by ADAMTS13 in plasma is essential to remove UL-VWF from endothelial surface and to subsequently reduce the size of VWF multimers in circulation (Figure 1).